import java.io.IOException;
import java.net.*;
import java.util.Scanner;

public class UdpEchoClient {
    private DatagramSocket socket ;
    private String serverIp ;
    private int serverPort ;

    public UdpEchoClient(String ip , int port) throws SocketException {
        this.socket = new DatagramSocket();
        this.serverIp = ip;
        this.serverPort = port ;
    }
    public void start() throws IOException {
        System.out.println("客户端启动");
        Scanner scan = new Scanner(System.in) ;
        while (true){
            System.out.println("输入请求=>");
            String request = scan.next();
            DatagramPacket requestPacket = new DatagramPacket(request.getBytes() , request.getBytes().length
             , InetAddress.getByName(serverIp), serverPort) ;
            socket.send(requestPacket);
            DatagramPacket responsePacket = new DatagramPacket(new byte[4096] , 4096) ;
            socket.receive(responsePacket);
            String response = new String(responsePacket.getData(), 0 , responsePacket.getLength());
            System.out.println(response);
        }
    }

    public static void main(String[] args) throws IOException {
        UdpEchoClient client = new UdpEchoClient("127.0.0.1" , 9090);
        client.start();
    }
}
